Design: The Case for Bringing Imaging Into the ED

In-ED imaging can improve efficiency, raise the quality of care and even help the bottom line. Dr. Manuel Hernandez explains how to design it right from the ground up.

As the ED has evolved, the role of advanced diagnostics has exploded in the evaluation and management of our patients. Beginning with simple roentgenograms and basic laboratory analysis, our diagnostic capabilities have expanded to include advanced non-invasive imaging that has largely replaced exploratory surgery and the “wait-and-see” approach commonly used in the absence of diagnostics.

The concept of housing imaging within the ED had gained popularity, though at differing rates. The most readily available data from the United States and other advanced systems has shown a steady increase in imaging utilization. For example, data from the United States has demonstrated a five-fold increase in CT studies ordered in paediatric cases from 1995 – 2008 (Larson). Flattening and even declining utilization trends are also beginning to exhibit themselves for adult patients in advanced systems where CT scans have been readily available for many years (Levin, Menoch).

Part of what has driven increased use of imaging can be attributed to increased availability and practice in high-liability environments. While there is limited peer-reviewed data to suggest a correlation between availability of imaging in-department and utilization rates, links between liability concerns and utilization have been demonstrated (Smith-Bindman).

The Case for In-ED Imaging

Planning for In-ED imaging begins with developing the business case for why investment in such expensive technologies will enhance performance, be it clinical quality, operational efficiency, financial performance or any combination of the three. Table 1 demonstrates the impact of imaging turnaround times on overall ED performance.

Looking at the cost of construction of unnecessary capacity and annual staffing costs to support patient care, the case for developing design solutions to reduce imaging turnaround times is clear. Building on the information in Table 1, Table 2 further explores the business case for in-ED imaging services.

Based on the information presented in Table 2, an investment in an in-ED x-ray unit would break even on the investment within 2-3 years of implementation, while a CT scanner would break even on the investment within 5-7 years, depending on the technology purchased.

Other studies have looked at the cost effectiveness of use of advanced imaging modalities as a part of the ED evaluation phase as a strategy for reducing the overall cost of care. For example, use of coronary CT angiography in the ED as a part of an in-ED cardiac rule-out pathway has been shown to reduce overall length of stay for low-risk chest pain patients while also significantly reducing the total cost of care for the patient encounter (Goehler). In situations such as this, the investment in an in-ED CT scanner could yield a quick return on the investment in the technology.

Imaging Modalities to Consider

Selecting the proper imaging technologies can have a direct impact on speed to diagnosis, initiation of definitive management and overall length of stay in the ED. The selection criteria for what imaging to include within the borders of the ED should, at a minimum, include the following:

The addition of diagnostic imaging technology in the ED is no small investment. Because of this investment requirement, it is important to consider whether or not the demand for imaging services justifies the investment. While there is no industry-wide benchmark for imaging volumes that justify investment in imaging, this author considers the information in Table 3 as a useful guideline.

ED Acuity and Special Patient Populations

As EDs develop more and more specialty services, the speed to diagnosis and definitive management becomes evermore important. Similarly, as patient acuity levels increase in the ED it can be expected that more and more demand for imaging services will develop. With this understanding in mind and based on current and future standards of care, this author considers Table 4 to be a useful guideline for in-ED imaging planning.

Distance of ED From Main Diagnostic Imaging Services

Studies analyzing the root causes of delayed ED imaging have indicated that order processing and patient transport times, along with imaging location can all impact imaging turnaround times. A study of three urban Canadian EDs demonstrated that turnaround times for plain x-ray studies were shorted in the ED with an imaging unit within ED, while turnaround times were over 50% longer when the x-ray unit was located remote to the ED (Worster).

Availability of Diagnostic Imaging Staff 24/7 or On-Call

Staffing the imaging areas of the ED is another important consideration for in-ED imaging services. Clearly, a CT scanner in the ED is of no benefit if there is no staff to run it. Once an imaging modality is located within the borders of the ED, it is expected the service will be available 24/7 through either an in-house or on-call staffing model.

Potential Impact on Cost of Care

Throughout this article, examples of how diagnostic imaging has impacted the overall cost of care have been presented. Bending the cost-curve of emergency care and the total cost of care are important considerations that can be meaningfully impacted by careful imaging planning in any ED design. For example, selecting advanced CT technologies with subsequent elimination of oral contrast preparation for abdominal CT scans has shown to reliably decrease length of stay by as much as two hours or more without compromising quality (Levenson, Hopkins, Hlibczuk, Anderson).

Designing the ED for Optimal Imaging Services

While previous ED designs typically centered on placing in-ED imaging services deep within the ED and clustered together newer designs are experimenting with decentralization of imaging services, placing each modality closest to its area of greatest demand. This said, as illustrated in Figure 2, extremely large EDs (annual census > 100,000 visits) may benefit from centrally locating in-ED imaging relative to all treatment stations by reducing travel distances for patients and staff.

Varying the location of the imaging modalities within the ED can have a significant impact on overall speed to imaging and length of stay for all but the largest EDs. One ED that moved its fixed x-ray unit from deep within the ED to be adjacent to triage noted a 25% reduction in length of stay for patients requiring x-ray studies (Horton). The logic of this design approach is that lower acuity, ambulatory patients tend to rely on the fixed x-ray unit, while higher-acuity patients tend to receive a higher number of portable x-rays in many EDs. Figure 2 demonstrates an ED design depicting a decentralized imaging model with x-ray located proximate to triage and lower acuity areas while CT is located closer to the trauma bays.

Figure 1 shows an ED design with x-ray immediately adjacent to triage. This design solution creates a patient flow that, where clinically-acceptable, allows the triage team to identify and order the appropriate imaging study with the patient receiving the x-ray prior to being placed in a treatment station with a resulting decrease in travel distances for the patient and staff.

Portable imaging technologies have also been shown to add value and should be planned for appropriately. A 2010 Canadian study assessed the impact of a portable CT scanner in rural community hospitals linked to larger referral center via a tele-stroke program resulted in increased ability to deliver thrombolytics to patients presenting with an acute ischemic stroke (Shuaib).

When planning for portable imaging modalities, the primary concerns in ED design are proximity and size. First, storage space for the portable units should be in close proximity to the staff using the technology and the patients most frequently requiring the corresponding imaging study. Second, ED treatment stations should be designed large enough to accommodate entry of the portable imaging technology into the room with the ability to easily access the patient from at least three sides.

Other important ED design considerations with respect to imaging focus on ensuring imaging staff have adequate workspace in proximity to where imaging services will be performed. Similarly, equipment necessary to process images should be immediately adjacent to where imaging studies will be performed to reduce overall staff travel distances and delays in study turnaround times. Equally important, locations where ED physicians and staff can view images should be readily available throughout the ED. This is most easily accomplished by ensuring adequate viewing monitors or, more recently, through the use of high-resolution portable tables with wireless connection to the imaging viewer.

An important non-facility design consideration is how linking EDs across a community can help reduce overall utilization of imaging modalities, particularly for patients being seen in multiple EDs or having multiple visits for the same complaint. One community developed a health information exchange that allowed all EDs to access the results of imaging studies performed at other EDs in the community. Access to previously-completed imaging studies resulted in a 64% decrease in repeat imaging studies for patients complaining of back pain (Bailey). Similarly, designing ED imaging services to support image import capabilities for patients being transferred to another ED for ongoing management has been shown to reduce reimaging (Bamberg, Sodickson). This would have the obvious benefit of reducing unnecessary radiation exposure and lowering the total cost of care. Figure 5 illustrates the design of a common imaging view room that can support both in-house and uploaded images.

Summary

Through careful planning, business case development and design, EDs can be developed to support best-in-class design features while enhancing the standard of care, improving overall efficiency and productivity of the ED, lowering length of stay and reducing the cost of care for multiple patient groups. Facilities planning new, renovated or expanded EDs are wise to carefully consider how diagnostic imaging will evolve and, based on this, what imaging should be considered for inclusion within the physical borders of the ED.